Block reward

Mining costs electricity and hardware. The block reward is what pays for it: whoever wins a block gets to write one special transaction, the coinbase, and pay themselves.

How much? Exactly two things, added together:

• the subsidy: brand-new PRL, set by the emission formula for the block’s height;
• the fees: whatever the block’s other transactions left over between their inputs and outputs.

Nothing else. Every node recomputes both and rejects a block that pays itself a single grain too much.

Try it

Pick a height and read its subsidy off the curve. The fee part depends on what the block contains.

What may a miner claim?

The rule is one comparison, run on every block:

The fees are easy to total: for each transaction, the inputs’ values minus the outputs’ values. The subsidy comes from the height:

A miner may claim less than allowed. The rule is “at most”, so nothing stops it, and the unclaimed part is simply never created: no later block can pick it up. That’s why the issued totals on these pages are a maximum.

Does block 130,825 add up?

Here is its coinbase, the first of its 115 transactions, mined by Kryptex on 20 October 2026:

Its first output pays cc84ce1d34000000: read little-endian, 223,838,373,068 grains to a Taproot address. The second output is the zero-value witness commitment. Now check it:

1. The subsidy at height 130,825

   ⌊2.1 × 10¹⁷ × 650,226 ÷ (781,051 × 781,050)⌋ = 223,833,660,195 grains.

2. The fees of the other 114 transactions

   Their inputs minus their outputs, summed: 4,712,873 grains.

3. The limit

   223,833,660,195 + 4,712,873 = 223,838,373,068 grains: exactly what the coinbase claims, to the grain.

Other blocks check out the same way:

Subsidies and fees are in grains; 1 PRL = 100,000,000 grains.

How big are fees, compared with the subsidy?

Tiny, for now. Block 130,825 had 114 paying transactions, and their fees came to about 0.047 PRL, roughly 0.002% of its reward. Typical payments on 20 October 2026 paid about 50 grains per vbyte; the floor is 1 grain per vbyte.

Many blocks carry no fees at all. In a scan of 200 blocks ending at 130,825 (20 October 2026), 107, or 53%, held only the coinbase. For those, the reward is the subsidy and nothing more.

As the subsidy keeps shrinking, fees will matter more. How a fee is set is on fees and vsize.

Why wait 100 blocks before spending?

Because a block can be undone. If a competing branch with more work replaces it in a reorg, its coinbase vanishes, and so do the coins it created. Ordinary transactions can usually be mined again in the new branch. A coinbase can’t: it belongs to the block that lost.

So the rules make new coins wait. A coinbase output from height h can only be spent in a block at height h + 100 or later. This is coinbase maturity, unchanged from Bitcoin:

By then, undoing the coinbase would mean out-working 100 blocks of the main chain. At the 194-second pace that’s about 5 hours 23 minutes of waiting.

What did the genesis block pay?

Nothing. The formula itself returns 0 for height 0, and the genesis coinbase has a single output worth zero, locked by a bare OP_RETURN, which can never be spent. As a belt-and-braces measure, the code also singles it out: “the coinbase for the genesis block is not spendable”.

Block 1, one second later, was the first to pay a reward: 3,229.64134063 PRL. There is no premine. The full story is on the genesis block.

var totalGrainOut int64
for _, txOut := range transactions[0].MsgTx().TxOut {
	totalGrainOut += txOut.Value
}
expectedGrainOut := CalcBlockSubsidy(node.height, b.chainParams) + totalFees
if totalGrainOut > expectedGrainOut {
	return ruleError(ErrBadCoinbaseValue, str)
}

if utxo.IsCoinBase() {
	originHeight := utxo.BlockHeight()
	blocksSincePrev := txHeight - originHeight
	if blocksSincePrev < int32(chainParams.CoinbaseMaturity) {
		return 0, ruleError(ErrImmatureSpend, str)
	}
}